1. Field of the Invention
The present invention relates to the training of aircraft pilots and more particularly to the training of pilots in simulators. Even more particularly, the present invention may be described as an isometric control stick for use in a part task training simulator.
2. Description of the Prior Art
There are a number of manual control designs for training aviators in existence today. Basically, however, the controls may be categorized into two types: active and passive. The active controller, usually called a control loader, generates control forces which are variable by computer commands. The passive controller is a hand control in which the control feel cues, i.e., control forces, are not variable during operation. The passive hand control is generally machanized in two configurations: the gimbal mounted hand grip and the isometric handgrip.
A control loading system, as an active controller, basically consists of a set of aircraft controls, a servoed loading system device, and an analog computer. Examples of control loading systems can be found in U.S. Pat. No. 2,804,698 to P. E. Grandmont, and U.S. Pat. No. 3,903,614 to John A. Diamond et al. Control loaders are utilized in high functioning aircraft simulators where pilot/aircraft stability or pilot control response to avionics equipment is evaluated or optimized. For cost and design reasons, the control loader is not feasible for control stick simulation in a partial task trainer.
The gimbal mounted system has appeared in numerous applications from flight controls to controlling arcade games. The usual mechanization of this type control attaches the handgrip to a 2-axis gimbal structure, thus providing the handgrip with pitch and roll motions. The major disadvantage of the gimbal mounted systems is that their attendant linkages, gears and cams tend to limit long term reliability.